VIENNA - UN nuclear inspectors will press again for access to a major
military facility in talks with Iran this week but the chances of
finding any evidence of suspected atom bomb research may have dimmed
because the site has been "cleaned up", Western diplomats and experts
say.

Visiting the Parchin complex has become a priority for the
International Atomic Energy Agency as it seeks to end what the West sees
as prolonged Iranian stonewalling of its investigation into allegations
of attempts to design a nuclear weapon.

Iran denies accusations
that it wants to develop nuclear weapon technology. But its refusal to
limit and be more transparent about its nuclear activity has led to
increasingly tough sanctions and sparked renewed speculation that
Israel, Tehran's arch-enemy, might bomb Iranian nuclear installations.

Citing
satellite images, Western diplomats say Iran has demolished some small
buildings and moved earth at Parchin in an apparent attempt to purge any
incriminating evidence from a site where the IAEA believe tests in a
steel chamber relevant to nuclear arms were carried out, possibly a
decade ago.

"I have heard that there is currently a lot of
clean-up going on at Parchin," one envoy said, who like other diplomats
said such work was only spotted after the IAEA mentioned Parchin in a
detailed report late last year.

Another
diplomat accredited to the IAEA said he believed Iran would not allow
access to the facility "unless they are extremely confident that there
will be nothing found."

Iran says Parchin, about 30 km (20 miles)
southeast of the capital Tehran, is a conventional military site and
has dismissed allegations aired about it as "ridiculous."

But the
IAEA is likely to express deepening concern about suspected
whitewashing efforts at Parchin in its upcoming quarterly report on
Iran's nuclear program, due next week, and how they may hamper its
inquiry, the diplomats say.

A US think-tank, the Institute for
Science and International Security (ISIS), said this month that
satellite imagery from Parchin showed "what appears to be the final
result of considerable sanitization and earth-displacement activity."

New IAEA report expected to show Iran enriching uranium

Talks
between senior IAEA and Iranian officials scheduled for Friday in
Vienna could offer a last-minute chance for Tehran to influence the
content of the report if it were to offer concessions regarding access
to sites, documents and officials.

The IAEA report - expected to
reiterate that Tehran is pressing ahead with its uranium enrichment
program - will be submitted to the agency's 35-nation governing board,
which meets on Sept. 10-14 with Iran likely to again dominate the
agenda.

This week's meeting between the IAEA and Iran will be
their first since talks in early June ended in failure, with Iran
setting conditions for how the inquiry should be conducted that were
unacceptable for the UN watchdog.

The IAEA said the two sides
would hold "further discussions on a structured approach to resolve
outstanding issues relating to Iran's nuclear program," referring to
suspicions of possible military dimensions to Tehran's atomic
activities.

No details were given. But the IAEA made clear in
earlier rounds of talks this year that its immediate request is to go to
Parchin. Iran says it must first agree a framework for the IAEA's
inquiry before possibly allowing access to the facility - a stance
dismissed by Western diplomats as delaying tactics.

It is unclear whether Iran will give any ground over Parchin at Friday's meeting at its diplomatic mission in Vienna.

Even
if it did allow UN inspectors to visit, they would probably uncover no
hard evidence of nuclear weapons-related work, according to nuclear
proliferation expert Mark Fitzpatrick at the International Institute for
Strategic Studies think-tank.

"The clean-up probably could not
totally remove uranium particles, but they wouldn't be enriched and Iran
would be able to offer exculpatory explanations," Fitzpatrick told
Reuters.